Year	Ratio
1970-01-01	0.960370004177094
1971-01-01	0.965210020542145
1972-01-01	0.975130021572113
1973-01-01	0.957679986953735
1974-01-01	0.984409987926483
1975-01-01	0.990230023860931
1976-01-01	0.986580014228821
1977-01-01	0.989470005035400
1978-01-01	0.983959972858429
1979-01-01	0.985639989376068
1980-01-01	0.983690023422241
1981-01-01	0.982410013675690
1983-01-01	0.985130012035370
1984-01-01	0.988070011138916
1985-01-01	0.987630009651184
1986-01-01	0.991670012474060
1987-01-01	0.992649972438812
1991-01-01	0.997789978981018
1992-01-01	0.990480005741119
1994-01-01	0.991569995880127
1995-01-01	1.001899957656860
1996-01-01	0.983940005302429
1997-01-01	0.981949985027313
1998-01-01	0.989769995212555
1999-01-01	0.990180015563965
2000-01-01	0.981700003147125
2001-01-01	0.992429971694946
2002-01-01	1.005149960517880
2003-01-01	0.996670007705688
2004-01-01	0.985759973526001
2006-01-01	0.991670012474060
2007-01-01	0.983150005340576
2008-01-01	0.995869994163513
2009-01-01	0.984910011291504
2011-01-01	1.000640034675600
2012-01-01	1.009230017662050
2013-01-01	1.010699987411500
2015-01-01	0.991119980812073